A study investigating microplastics (MPs) and nanoplastics (NPs) in agricultural settings has found they reduced plant growth and entered plant tissues through the soil, raising new concerns about food safety and human exposure.
The study, led by Griffith University, tested how micro- and nanoplastics behaved in soil using realistic conditions using particle types, surface properties, sizes and concentrations representative of those found in agricultural systems.
Using wheat and tomato plants, the team, led by Dr Shima Ziajahromi from Griffith’s Australian Rivers Institute, found MPs reduced plant growth and chlorophyll content, with fibre-shaped plastics (originating from synthetic textile) having the most effects.
This suggested potentially serious implications for food production.
“We also found that plants can trap MPs in the soil, reducing their movement in the environment, but this may also lead to accumulation around roots,” Dr Ziajahromi said.
“Critically, we found NPs were taken up into plant tissues and transported within the plant, including its leaves.
“These findings demonstrate that agricultural soil is not just a sink for plastics, but a pathway into the food systems – meaning they could end up on our plates.
“This highlights the need for improved environmental management practices, targeted mitigation strategies, and evidence-based regulations to control plastic inputs and reduce risks to food systems and human health.”
Unlike previous laboratory studies that often used unrealistically high concentrations or pristine plastics, the research led by the Griffith team used aged plastics, realistic particle sizes, actual polymer types, and concentrations typically found in biosolids and agricultural soils.
The key findings showed:
“These results present potential risks to food safety, emphasising the need for new regulatory approaches informed by real-world plastic exposure scenarios,” Dr Ziajahromi said.
The study ‘ Microplastic uptake and impacts on crops under realistic exposure: implications for soil–plant systems ’ has been published in Environmental Science and Pollution Research .
Environmental Science and Pollution Research